"Dr. Jervis and I can walk," Walter Hornby suggested. "We shall probably get there as soon as you, and it doesn't matter if we don't."
"Yes, that will do," said Mr. Lawley; "you two walk down together. Now let us go."
We trooped out on to the pavement, beside which a four-wheeler was drawn up, and as the others were entering the cab, Thorndyke stood close beside me for a moment.
"Don't let him pump you," he said in a low voice, without looking at me; then he sprang into the cab and slammed the door.
"What an extraordinary affair this is," Walter Hornby remarked, after we had been walking in silence for a minute or two; "a most ghastly business. I must confess that I can make neither head nor tail of it."
"How is that?" I asked.
"Why, do you see, there are apparently only two possible theories of the crime, and each of them seems to be unthinkable. On the one hand there is Reuben, a man of the most scrupulous honour, as far as my experience of him goes, committing a mean and sordid theft for which no motive can be discovered—for he is not poor, nor pecuniarily embarrassed nor in the smallest degree avaricious. On the other hand, there is this thumb-print, which, in the opinion of the experts, is tantamount to the evidence of an eye-witness that he did commit the theft. It is positively bewildering. Don't you think so?"
"As you put it," I answered, "the case is extraordinarily puzzling."
"But how else would you put it?" he demanded, with ill-concealed eagerness.
"I mean that, if Reuben is the man you believe him to be, the thing is incomprehensible."